1. Field of the Invention
The present invention is related to a suspension board assembly sheet with circuits and a method for manufacturing the suspension board assembly sheet with circuits.
2. Description of Related Art
Actuators are used in drives such as hard disk drives. Such an actuator includes an arm provided rotatably around a rotation shaft, and a suspension board with circuits (hereinafter referred to as a suspension board) for a magnetic head that is attached to the arm. The suspension board is a printed circuit board for positioning the magnetic head at a desired track of a magnetic disk.
The suspension board includes the magnetic head and is connected to another electronic circuit. A conductor pattern is formed at the suspension board, and an electric signal is transmitted between another electronic circuit and the magnetic head through the conductor pattern. The plurality of suspension boards having such configuration are formed to be integrally supported at a common support frame in the process of manufacturing (see JP 2012-18984 A, for example).
In each suspension board, a ground wiring layer and a signal wiring layer are formed on a metallic support substrate with an insulating layer sandwiched therebetween. The ground wiring layer and a metallic support substrate are electrically connected by a plated via portion that penetrates the insulating layer. Further, in the support frame, a conductor layer is formed on the metallic support substrate with the insulating layer sandwiched therebetween.